Presenter: Peter Kayaert 13th Experts "Live" CTO Workshop 17th–18th September 2021 - Florence, Italy

1. Ref: 2021 Mar;97(4):646-655. doi: 10.100/ccd.29072. Epub 2020 Jun 17.

2. Background
1. Short-term prognostic benefit of PCI is questioned (ISCHEMIA) and
focus currently shifts from ischemia relief to symptom relief
• Succesful CTO PCI can improve symptoms and QOL (EURO CTO, IMPACTOR CTO)
• Persistent/recurrent angina and ischemia in ≈1/4 patients
2. Highest benefit of PCI with low pre-PCI and high post-PCI iFR/FFR
Ref: Maron NEJM 2020; Werner EHJ 2018; Obedinskiy JACC Cardiovasc Interv 2018; Tonino NEJM 2009;
Argawal JACC Cardiovasc Interv 2016; Jeremias JACC Cardiovasc Interv 2019

3. Ref: Johnson JACC 2014; Al-Lamee (Orbita) Circulation 2018
Highest benefit from revascularization with lowest iFR/FFR

4. Ref: Johnson JACC 2014; Lee JACC Cardiovasc Intv 2017; Werner JACC 2003
post PCI post-CTO PCI
(in BMS era also associated with reocclusion)
Suboptimal post-PCI FFR predicts adverse long-term clinical outcome

5. Ref: Piroth Circ Cardiovasc Interv 2017; Hakeem JACC Cardiovasc Interv 2019; Patel TCT connect 2020: DEFINE-PCI 1y results
Post-PCI FFR >0.86-92 and iFR ≥0.95 associated
with better outcome and symptom improvement

6. Aims

to demonstrate through instant wave-free ratio (iFR) measurements that
1. myocardium distal to a CTO is ischemic
2. ischemia is reversible by PCI
3. iFR assessment after PCI can be used to evaluate & optimize CTO PCI results

7. N=63/81 N=81/81 N=21/81
Methods
BWGCTO
registry
substudy
Consecutive
inclusion
8 Belgian
Centers

9. Ref: Werner EHJ 2006 (N=62 preCTO PCI);
Sachdeva CCI 2014 (N=50 pre+post CTO PCI);
Lee JACC Cardiovasc Intv 2017 (N=74 pre+post CTO PCI)
Ref: Kayaert CCI 2020 (N=63 pre+post CTO PCI)
Key Findings

10. 1. In CTO patients planned for PCI based on contemporary evidence and guidelines,
profound ischemia as assessed by iFR was present in all patients regardless of
well-developed collaterals
2. CTO PCI led to an immediate iFR increase, in most cases above the 0.89 cut-off,
indicating reversal of ischemia

11. 77 patients (95%) underwent post CTO PCI iFR: median iFRpost was 0.93 [0.86;0.96]
23 patients (30%) had an iFR  0.89
21 patients underwent iFR pullback
9 patients (43%) had gradual iFR rise
suggesting diffuse disease and/or negative
remodelling
12 patients (57%) had focal iFR step-up
suggesting a focal isssue and got further
result optimization
residual focal lesion
> Stenting (n=9)
focal stent underexpansion
> Postdilatation (n=3)
iFR improved to 0.90 [0.89;0.94] (p=0.002);
only 2 patients still had final iFR ≤ 0.89

12. 3. 30% of the patients still had an iFR ≤0.89 after angiographically successful CTO
PCI, indicating persistent ischemia.
In more than half of cases this was due to a focal issue.
4. Optimization based on iFR pullback was able to correct most sub-optimal CTO
PCI results due to focal issues (and about half of all sub-optimal results)

13. Conclusions
1. Patients with a good indication for CTO PCI are always ischemic
2. Ischemia can be relieved by CTO PCI, but up to 30% of patients with good
angiographic results will have persistent ischemia
3. Hemodynamics often improve over time, but immediate (or second-stage) optimization
efforts should be made for the best hemodynamic outcome
4. iFR should be considered post CTO PCI (like imaging) as it may reveal residual
flowlimiting disease or suboptimal stent results that may lead to optimization and
potentially better hemodynamic and clinical outcome

14. Future perspectives
1. Consider physiological assessment (with invasive or possibly angiography-derived
physiological indices) for result evaluation and immediate optimization where possible
as symptom relief may depend on it
2. Consider FU angiography and staged optimization in 3-4 months in patients
with sub-optimal initial physiologic results (especially if symptoms persist)